As an afterthought, could this card be replaced (at a later, more cash-rich, date) with any ease?

Sorry.. just not gonna happen, basically. With very few exceptions*, laptop graphics chips are soldered onto the motherboard, and the rest of the board is designed with that specific chip in mind. Just as with the crappy graphics in my own laptop, you're stuck with it.

*Laptops which actually use a proper separate graphics card do exist, but they are generally bulkier and heavier than typical laptops, are more expensive, and the cards must be custom-tailored for the laptop. Standard desktop cards won't fit. So the upgrade options tend to be limited.

_________________Most games have some sort of paddling-pool-and-water-wings beginning to ease you in: Oolite takes the rather more Darwinian approach of heaving you straight into the ocean, often with a brick or two in your pockets for luck. ~ Disembodied